Studies were conducted with resmethrin-impregnated netting to determine its potential as a clothing impregnant for protecting human hosts from blood-feeding arthropods. Tests were conducted in a laboratory olfactometer with Aedes aegypti (L.) and Anopheles albimanus (Wiedemann). Outdoor cage experiments were conducted with these 2 species and the stable fly, Stomoxys calcitrans (L.). Field tests were conducted with Ae. taeniorhynchus (Wiedemann) and the deer fly, Chrysops atlanticus Pechuman. Resmethrin showed no repellent activity (i.e., alternating approach to an attractive host) against these species but did show very rapid intoxication and behavioral changes resulting in complete or high level protection from biting as well as kill of attacking insects. There was no evidence of vapor toxicity in these tests. In olfactometer tests Ae. aegypti and An. quadrimaculatus were not repelled but died from momentary contact with treated netting. In cage tests these 2 species and stable flies were killed by momentary contact while attempting to feed on hosts. In field tests, protection was obtained against a deer fly and Ae. taeniorhynchus and the numbers of attacking insects was reduced to low levels.